In the field of electrophotographic printing, also known in the art as laser jet printing, it has been one common practice for several years now to pass the printed media, such as paper or transparencies with the just-printed text or graphics thereon, between a fuser roller and an idler pressure roller to burn-in or fuse-in the text or graphics on the media and thereby eliminate the possibility of smearing the media and thus enhance the overall permanent nature of the generated document. Examples of these types of fuser systems may be found in U.S. Pat. No. 4,475,896 issued to Bains and U.S. Pat. No. 4,505,695 issued to Billings, both incorporated herein by reference.
In the prior art construction of small desk top type electrophotographic printers, it has further been a common practice to route the fused media along a paper path which extends from the fuser roller normally located near the backside of the printer and into an output paper tray located adjacent the front side of the printer. In conventional operation of these printers, the output documents are stacked face down in the output paper tray. The paper path routing arrangement for controlling the flow of paper motion would normally include a pair of guide rollers positioned in the paper path and located somewhere between the fuser roller and the output paper tray and operative to direct and drive the paper along its contoured path sometimes approaching 180.degree. from the location of the fuser roller to the output paper tray.
A problem that arises using the above configuration and design for media fusing and media motion control results from the fact that the fused media leaving the fuser roller is cooling while it passes along the contoured path. During this cooling period, the paper is susceptible to retaining the contour of the paper path to which it is subjected. The net result of this operation is the production of an undesirable curl in the printed media to the detriment of subsequent paper stacking, paper copying, and other forms of paper handling once the paper reaches the output paper tray. It is the solution to this latter problem to which the present invention is directed.